[OLPC Networking] [Server-devel] RSSI value questions

[david at lang.hm]

On Thu, 3 Apr 2008, Michail Bletsas wrote:

> Let's not forget that you need some fixed reference points.
> In commercial systems, the locations of the access points are well known.
> In ad-hoc networks the best that you can hope for is a topological map.

the assumption was that the measurements are being done from fixed points. 
either the school server antenna locations, or the known locations of 
specific assistant laptops.

without known locations you can't do much.

David Lang

> M.
>
>
>
> server-devel-bounces at lists.laptop.org wrote on 04/02/2008 01:45:14 AM:
>
>> Ryan,
>>
>> Like Ben said, inducing the physical layout of the network from metrics
>> such as RSSI will give you poor results for various reasons. What
>> "Space" did was to average arrival rates from direct neighbors over a
>> "long" period of time (anywhere between 1 and 10 seconds) to avoid
>> highly temporal effects like multipath and noise. Even so, the result is
>
>> only a rough layout of the network. If you'd like to achieve better
>> accuracy I thing you should combine other ideas like sound measurements,
>
>> as Ben suggested.
>>
>> Pol
>>
>>
>
>